In order to provide a good decorative effect, some patterned skeletons are designed, for example a deer skeleton (1) as shown in FIG. 1. A light string is winded on the skeleton (1) and bulbs (2) of the string emit rays outward to display the patterned outlook of the skeleton (1) that reaches the preset decorative purpose, especially at night. But in the conventional design, if the bulbs (2) are not enough, the lighting effect of the patterned skeleton will be poor. If more bulbs (2) are provided, the cost will be high and it increases the total weight that is a burden to the patterned skeleton. Further, power supplier will become another problem.